Cord stretching apparatus



Oct. 3, 1939. l.. M. coTcHETT I 2,174,688

l CofD STRETCHING APPARATUS Filed'sept. 8, 1958 Patented Oct. 3, 1939 UNITED STATES PATENTl OFFICE CORD STRETCHING APPARATUS New Jersey Application September 8, 1938, Serial No. 228,906

4 Claims.

This invention relates to apparatus for imparting a permanent stretch to cords, such as tire cords, and the invention is directed more particularly to a pair of free-running, grooveless rolls adapted to be operated by the take-up pull exerted upon the cord, to thereby stretch the cord as rit passes around these rolls in successive runs.

It has been found that certain improved properties are imparted to a tire cord by permanently stretching, attenuating or elongating the same, since the stretching decreases the size of the cord without correspondingly reducing its ystrength and has other advantages.

It has been proposed heretofore to stretch cords and ropes by passing a number of convolutions thereof around spaced conical grooved rolls so that the successive runs of the cord or rope travel along paths of slightly increased length to eiect the desired stretching operation, but in these prior constructions, mechanism was employedV for positively driving one or both of the stretching rolls. 'I'he driving of such roll or rolls always presented a troublesome problem Hsince their speed of rotation had to be correlated to the speed at which the cord or rope was being Wound upon the take-up spool.

The present invention relates to an extremely simple construction which may be quickly and easily threaded up ready to eiect the stretching operation and which does not require any power to operate the same other than the takeup pull that is exerted upon the cord being stretched.

It is well known that when a thread, cord, rope, or the like is supplied to a rotating drum to be wound thereupon, it will tend to approach the drum in a plane at right angles to the axis of the drum rotation rather than at an angle `to such plane. In carrying out the present invention, advantage is taken of this tendency by mounting a pair of stretching rolls so that they will rotate about converging axes, and as a result of this arrangement each run of the cord wound around the stretching rolls approaches the spaced rolls at right angles to their respective axes oi rotation. In this manner the successive runs of the cord are kept spaced from each other by their tendency to approach the rolls at right angles to their converging axes By employing the free-running, grooveless, tapered stretching rolls herein contemplated it is unnecessary to .take any special care to space the successive runs of the cord as it is manually wound repeatedly about the rolls, since it is found that as soon as a take-up pull is exerted upon the cord to advance the same about the stretching rolls, the successive runs of the cord will automatically assume a spaced relation to each other, due to the converging arrangement of the axes about which the rolls rotate. Therefore, all an operator has to do, in starting the cord stretching operation is to wrap the cord around therolls the specified number of times, and when the operation begins that draws the cord forward about the stretching rolls the cord runs will separate automatically.

A primary feature of the present invention resides in the free-running grooveless stretching rolls which are adapted' to be operated by the take-up pull exerted upon the cord being stretched, and in the arrangement of these rolls whereby the successive runs of the cord are spaced automatically from Veach other and are gradually stretched as they advance from one run to another.

The above and other features` of the present invention and novel arrangement of parts will be more fully understood from the following uescziption when read in connection with the accompanying drawing illustrating one good practical form thereof.

In the drawing:

Fig. 1 is a side elevation of a pair of cord stretching rolls constructed in accordance with the present invention;

Fig. 2 is a front elevation of the mechanism shown in Fig. 1; and

Fig. 3 is a view similar to Fig. 1 and illustrates the same stretching rolls shown in Fig. 1 except that these rolls are spaced about twice as far apartin Fig. 3 asin Fig. 1.

In'the embodiment of the invention illustrated in the drawing I constitutes a supporting bracket or plate adapted to support the spaced fixed shafts II and I2, which shafts rotatably support the free-running tapered stretching rolls I3 and I4. In the construction shown the shaft II is rigidly secured to the supporting plate I0 at the desired inclination by drilling or otherwise forming a hole through thev plate I0 at nearly a right angle thereto to thereby receive the shank portion of the shaft II. One face of the plate I0 is cut away at the angle at which this hole is formed to provide a seat shoulder I5 formed upon the shaft II, opposite face of the plate I0 is similarly cut away to form a seat for the washer I6. The outer end of the shank of the shaft II is threaded as shown to receive the clamping nut I1, whereby this shaft II may be firmly clamped in place upon the plate I0 by tightening the nut I'I. 'I'he shaft I2 may be provided with similar means for firmly securing it in place upon the plate I0 at the desired distance from the shaft II and at the desired inclination to this plate. I

The stretching rolls I3 and I4 are .preferably given the tapered or frustro-conical shape shown and each roll may 'be provided with the end anges I8 and I 9 shown.` These rolls are prefand the with parts in section for theerably provided with anti-friction bearings, not shown, so that they will run freely upon supporting shafts. Each shaft is preferably provided` .at its outer end with a grease tip 20.

ing operation.

In each view the cord C is illustrated as passing through a guide eye 2| as it is drawn from some source of supply (not illustratedi. This guide eye is provided to direct the cord C about the desired portion of the tapered roll I3.

It will be noted upon examining either'fFlg. 1

or Fig. 3 that the cord C passes from the guide 2I to the roll I3 and halfway about this roll in a plane that passes through the guide 2I at right angles to the axis of the shaft I I. It will also be noted that this cord then passes from the point at which it leaves the small end of roll I3, to the roll I4 along a plane disposed at right angles to the axis of the shaft I2 and passing through the cord delivery point upon the roll I3. It will therefore be seen that all of the rear runs of the cord C lying at the far side of the rolls are illustrated in Figs. 1 and 3 as travelling towards the roll I3 along spaced planes i disposed at right angles to the axis of the shaft I I, and that all of the front runs of this cord travel towards the roll I4 along spaced planes disposed at right angles to the axis of the shaft II and the second mentioned planes are disposed at right angles to the axis of the shaft I2, it will be apparent that these two sets of planes are disposed at an angle to each other corresponding to the angle atwhi'oh the axes of the shafts II and I2 converge towards each other. It therefore follows thatA the distance the wraps are spaced apart about the stretching rolls will be proportional to the angle formed by the axes about which therolls rotate and also to the distance between theaxes at the point under consideration.A This is'clearly illustrated in Fig. 3 where the rll supporting axes converge towards each other at the same angle as in Fig. 1, but these axes are spaced approximately twice as far apart as in Fig. 1.

Any desired type of take-up means may be employed to draw the cord C, forward from the stretching mechanism of the present invention, and in Fig. 3 a capstan 22 which may be of well known construction, is shown as constituting the means for pulling the cord C- forward about the stretching rolls to thereby rotate the rolls I3 and I4 and impart the desired permanent stretch to the cord. The capstan may be supported and driven by the shaft 23.

It will be understood from the foregoing that no power is required to rotate the rolls I3 and I4 other than that exerted by the take-up means 22 upon the cord C. The cordstretch'ing device of the present invention may be located wherever It is here desired to point out that the amount of stretch to be imparted to the cord may be increased or decreased as desired by (1) changing the distance between the axes II and I2 to thereby vary the length .of the runs being stretched, (2) changing the taper of the rolls I3 and I4 or the inclination of the shafts II and I2 to increase or decrease the change in the successive. lengths of the runs of the cord being stretched (3) changing the number of windingsr of the cord about the rolls to thereby increase or decrease the'number of runs being stretched.

If it is desired to subject a relatively long length of cord C simultaneously to the stretching operation, then the rolls will be spaced a substantial distance apart as in Fig. 3 rather than close together as in Fig. 1.

Having thus described my invention what I claim and desire to protect by Letters Patentis:

1. In a cord stretching apparatus a pair of l free-running, grooveless, tapered rolls rotatably supported in spaced relation to each other to rotate about converging axes and arranged so that the tapered surfaces of each roll converge in the opposite direction to that in which said axes converge and to an amount to stretch the cord, said rolls having the cord to be stretched passed thereabout in spaced runs that travel successively towards the larger ends ofthe rolls, and means for pulling the leading portion of the cord forward to thereby rotate both rolls and stretch the cord along said runs.

2. In a cord stretching apparatus a pair of free-running, grooveless, tapered rolls rotatably supported in spaced relation to each other to rotate about converging ax and arranged so that the tapered surfaces of each roll converge lill in the opposite direction to that in which said axes converge, said rolls having the cord to be stretched passed thereabout in successive runs that increase in length as they advance from the smaller toward the larger ends of the rolls, and means for pulling the leading portion of the cord forward to thereby rotate both rolls and stretch the cord in saidruns.

3. In a cord stretching apparatus a pair of free-running, grooveless rolls rotatably supported in spaced relation to each other to rotate about converging axes, and at least one of said rolls l being tapered to thereby stretch the cord as it travels from the smaller toward the larger end of the tapered roll, said rolls having the cord to be stretched passed thereabout in successive runs that are spaced by the tendency of each run to approach a roll at right angles to its axis of rotation, and means for pulling the leading portion of the cord forward to thereby rotate both rolls and stretch the cord in said runs.

4. In a vcord stretching apparatus a pair 'of free-running, grooveless, tapered rolls rotatably supported in spaced relation to each other'to rotate about converging axes land the tapers of said rolls being sufficient to stretch the cord as it travels from the smaller towards the larger ends of these rolls, said rolls having the cord to be stretched passed thereabout in successive runs that are spaced by the tendency of eachrun to approach a roll at right angles to its axis of rotation, and means for pulling the leading portion of the cord forward to thereby rotate both rolls and stretch the cord in said runs.

LOUIS M. COTCHETI. 

